Points create a later choice
Dead Target: Shoot Zombies explicitly links defeating zombies with earning points for weapon upgrades. Before spending, identify what you want a change to address. Are you misunderstanding the tap action, selecting a target too late or encountering a limitation the interface actually describes? Those questions should be separated; a purchase cannot automatically solve uncertainty about how the controls work.
Inspect the upgrade information
Read the properties shown beside the available option. A larger illustration or a higher price does not establish a particular effect. If the game names a change, compare that change with the problem you identified. If no useful property is stated, treat a purchase as an experiment rather than describing it as the optimal next step for every player.
Check the result narrowly
After upgrading, observe the same kind of visible situation when possible. Notice whether the stated property changes the part of the encounter you meant to improve. Several other things may change between attempts, so one favorable result does not prove a universal advantage. The control field says to tap to shoot, but the record provides no ammunition system, weapon statistics or enemy schedule. This note offers a spending question, not a tested combat build or a survival guarantee.
Give weapon spending a reason grounded in the current zombie encounter.